2 Answers
2

You can't start a GUI app on boot because it needs to be attached to a graphical session, the graphical session is only setup after you login.
You could set it up to start when you login:

System -> Preferences -> Start applications

Add whatever command is required to start it, if it needs admin privilegs you may need to change your /etc/sudoers configuration so that you can start the app with admin privileges without asking for the password.